For example, EP 1583680B1 (Reference 1) discloses a steering apparatus that realizes adjustment of both tilt operation and telescopic operation with a single motor by switching power of the single motor to either the tilt operation or the telescopic operation using a power switching mechanism. In Reference 1, the motor outputs a driving force via a speed reducer to rotate a spindle (a male screw), and two nuts (female screws) meshing with the spindle at all times are disposed and respectively connected to a tilt link and a telescopic link. Since each nut includes a lock mechanism, and when the lock mechanism is locked, the nut is restrained from rotating with respect to the spindle, the nut moves in an axial direction of the spindle when the spindle rotates. That is, when the tilt mechanism-side nut moves, the tilt operation is performed, and when the telescopic mechanism-side nut moves, the telescopic operation is performed. When the lock mechanism is unlocked, the nut idles with respect to the rotation of the spindle and thus, the tilt operation or the telescopic operation is not performed. The following is examples of the lock mechanism: engagement and disengagement of a lock pin by a solenoid, an electromagnetic brake, an eddy current brake and the like.
In the steering apparatus disclosed in EP 1583680B1 (Reference 1), since each of the tilt mechanism-side nut and the telescopic mechanism-side nut needs the lock mechanism, one motor can be used with certainty whereas any reduction effects in the number of components, costs and mass cannot be expected. Since the tilt mechanism-side nut and the telescopic mechanism-side nut are disposed in series with each other, a total length of a steering column becomes great and mountability deteriorates.